In mail production equipment, various activities take place for the purpose of producing mail pieces. Such activities include the selection of inserts, the collection and stacking of the selected inserts, the placing of the inserts into an envelope and the sealing of the envelope to form the mail piece. In order for the inserts to be stuffed into an envelope, the mouth of the envelope may be opened so as to be able to receive the inserts.
Typically, envelopes do not have uniform characteristics i.e., their flaps may be curled in different directions. Some envelopes flaps have a full curl and other envelope flaps are curled on the flap glue line. Some other envelope flaps exhibited both of the above characteristics. Before material was inserted into the envelope, the prior art moved the envelope between an idler roller and a drive roller. Then the envelope engaged a second idler roller while a flap opener blade moved towards the body of the envelope. The foregoing caused the envelope to assume the shape of the circumference of the drive roller, which caused the envelope flap to spring away from the body of the envelope. The apex of the flap opener blade was positioned close to the body of the envelope and moved towards the flap fold of the envelope. At this point the flap opener blade would be wedged between the body of the envelope and the oncoming flap. As the envelope continued to be driven, the flap of the envelope would be opened by the flap opener blade. Now the envelope would move towards an inserter station so that material may be inserted into the envelope.
Although such devices worked well with production mail equipment, sometimes the envelope flap failed to open. This was caused by the flap finding the gap between the apex of the flap opener blade and the body of the envelope. The envelope would move to the inserter station with a closed flap. A sensor may be present to detect the closed flap and cause the system to come to a temporary halt. The envelope having the closed flap would be purged and then the insertion process would continue. If, the above condition persisted then the operator of the device would have to remove the envelopes having the closed flaps. This greatly reduced the efficiency of the inserter. If, no sensor was present, a closed envelope flap would cause the inserter to jam.
A disadvantage of the prior art was that a large gap between the body of the envelope pressed against the drive roller and the apex of the flap opener blade was required to insure that the flap opener blade never engaged the body of the envelope and/or the drive roller preventing the flap opener blade from springing back to its unactuated position.